First enable the manual gateway for your store, either in the dashboard or through the API:

PUT to /v2/gateways/manual

"data": {
"type": "gateway",
"enabled": true
}
}

Checkout your order as normal. Then authorize the payment using the manual gateway:

POST to /v2/orders/:orderID/payments

"data": {
"gateway": "manual",
"method": "authorize"
}
}

This will create a transaction on the order with the manual gateway. Once you have received payment, you can capture the transaction to mark the transaction & order as paid. (To find the transaction ID, you can GET to /v2/orders/:orderID/transactions)

I’m currently evaluating Moltin, but I don’t want credit card details to pass through my system. Could this be a solution? i.e. set the payment gateway to “manual”, use Stripe’s hosted payment solution, and then manually set the order to “paid” when the payment has been received?